The present study allowed to carry out a thermal characterization of concrete and cement mortar. Thermal tests were carried out with the KD2 Pro device, on concrete and mortar samples taken from twenty-six (26) construction sites of office buildings and two (2) industrial production units in the city of Ouagadougou. The tests were carried out on rectangular specimens after four weeks (4) of conservation on the site of construction or production of materials. This study seeks to determine the thermal properties of the materials, in particular the thermal conductivity, the thermal diffusivity and the thermal capacity of the samples, in the real conditions of execution of the buildings and environment. The thermal conductivity varies from 1.413 to 1.965 W/m•K, 0.940 -1.658 W/m•K and 0.703 -1.149 W/m•K respectively for concrete, cinder block mortar and plaster mortar. Regarding the other properties, especially the capacity and thermal diffusivity, the values vary respectively, from 1070.59 -1974.67 kJ/kg•K and (3.74 -6.70) × 10 −7 m 2 /s for concrete, from 1123.69 -1586.81 kJ/kg•K and (3.38 -5.65) × 10 −7 m 2 /s for plaster mortar and 1202.51 -1736.01 kJ/kg•K and (3.82 -7.36) × 10 −7 m 2 /s for the mortar of building blocks. The conductivity, capacity and thermal diffusivity of industrial mortar vary from 1.019 -1.229 W/m•K, 792.18 -1862.58 J/kg•K and (2.75 -6.80) × 10 −7 m 2 /s, respectively. Only the correlations made between the thermal properties and the density of the samples of the plaster mortar, give good relations namely R 2 = 0.9308 for the thermal conductivity, R 2 = 0.

The method used to evaluate the quality of concrete in structures includes, among other things, compressive strength testing of specimens cast on site. This method has shortcomings due to the non-uniformity in their formulation processes of the concrete studied in laboratories and that of the structure on site and the tardiness in obtaining test results. This is why the development of reliable methods of non-destructive assessment of the compressive strength of concrete in situ is essential for a better performance assessment of structures.There are a multitude of non-destructive methods, but in this article, the ultrasonic pulse velocity (UPV) and the rebound hammer (RH) are the methods used as they are easy to get manipulate, accessible and permit fast access to results. Analyses using single and multiple linear regression methods have been carried out with the results from compression tests and measurements of pulse velocity and rebound indices carried out between February and April 2018 on over 90 specimen samples in total. This resulted in correlation equations for the in-situ estimation of the compressive strength of the concrete studied.